Nikujaga is, as its name suggests, meat (niku) and potatoes (jagaimo) stewed together. It’s one of the signature dishes of the modern Japanese kitchen; a chef who cooks nikujaga well knows the way to his or her partner’s heart, it was once said. Either beef or pork can be used. If thinly sliced meat is unavailable at a local store, just cut a slab of steak or other meat into small slices.